Dampening rollers



Jan. 3, 1961 M. c. swoPE 2,966,724

DAMPENING ROLLERS Filed Feb. 6. 1959 Fig. lb I2 I.

United States Patent DAMPENING ROLLERS Morris C. Swope, Bryn Mawr, Pa.,assignor to Perfex Corporation, Bryn Mawr, Pa., a corporation ofPennsylvania Filed Feb. 6, 1959, Ser. No. 791,703

4 Claims. (c1. 29-120 This invention relates to dampening rollers foroffset printing machines and has for an object the provision ofdisposable dampening rollers of high quality.

As well understood by those skilled in the art, dampening rollers havepresented annoying delays in the operation of offset printing machinesbecause of the relatively short life of the covering required to carrythe water or other dampening media to the printing plates. Because ofthe wear of the dampening surfaces numerous proposals for the renewal ofsuch surfaces have been made. It has been further proposed to provide onpaper or fiber tubes dampening materials which may be considered in thedisposable class, at the option of the printer. So far as known, thesesuggestions have left much to be desired and particularly in theprovision of disposable dampening rollers which can be applied toexisting printing machinery of the offset type without the need ofmodifying the shafts and shaft supports to take care of the disposabledampening roller.

It is an object of the present invention to provide a dampening rollerwhich may be used quickly to replace a roller on a machine, the surfaceof which has outlived its usefulness.

In carrying out the invention in one form thereof, there is provided alow-cost inner core preferably made up of a large number of turns ofpaper. Such spirally wound inner cores are strong and to each there isadhesively secured the moisture-carrying material. Each core hasassociated therewith core elements which not only form a drivingengagement with the core but also are adapted to journal the core and toform a driving connection with other equipment for rotation of thedampening roller as needed in printing operations.

For further objects and advantages of the invention, reference is to behad to the following description taken in conjunction with theaccompanying drawings, in which:

Fig. 1 is a sectional view of a dampening roller embodying theinvention;

Fig. 2 is an end view of the roller of Fig. 1;

Fig. 3 is a side elevation of a plastic core plug for the roller of Fig.l; and

Figs. 4 and 5 are sectional views of modified forms of the invention.

Referring now to Fig. l, the dampening roller comprises a low-cost innercore 11 made of spirally wound paper and having a substantial thicknessto impart the required rigidity and strength to the roller as a whole.The paper as it is wound is coated with an adhesive so that the finishedcore is a laminated solid unyielding mass. To the outer surface of thecore 11 there is adhesively bonded, as at 12a, the moisture-carryingmaterial 12. The adhesive is of a moisture-resistant type, such forexample as National Adhesives No. l0-R-3 054. The moisture-carryingmaterial of molleton, velveteen, pile fabric and the like is preferablyspirally wound upon the core 11. When spirally wound on the 7 PatentedJan; 3, 1961 lC V core and secured thereto by an adhesive of thepermanently setting type, there is eliminated entirely the possibilityof loosening of the moisture-carrying material during operation, amatter which has given concern in the prior use of pressure-sensitivecements or adhesives.

Within the respective opposite ends of the core 11 are disposed moldedor machined inserts 13 and 14. These inserts are preferably made of aplastic or resin material of the high-impact type, a number of which areavailable on the market, such as nylon, and including the resins such ashigh-impact styrene, polyethylene, and the resins of the phenolic type.

Each of the plastic inserts 13 and 14 is adhesively secured to the core11, glue-carrying passages 13a and 14a being provided for the adhesive.Preferably each insert is made slightly oversize so that it is alsodisposed in a press-fit relation within the opposite ends of the core.As best shown in Fig. 2, the outer flange portion of each insertincludes projections such as 14b and 14c engageable with complementaryrecesses in a driving member for power drive of the dampening roller.Insert 13 has like driving lugs 13b and 13c.

The exposed surfaces of the core 11 are treated with amoisture-resistant material such as cellulose acetate or a cumar-indeneresin solution, or the like.

Dampening rollers as disclosed in Figs. 1 and 2 have been found to behighly satisfactory in operation and readily adapted for immediateinstallation in existing printing machinery. They lend themselves toready replacement of dampening rolls, the coverings of which have beenused beyond their useful life. The cost, in view of the savings inshut-down time, justifies their use as disposable items. Their useavoids entirely the troublesome operations heretofore required toreplace the moisture-carrying covering materials whether they be of thestocking type or whether they include pressure-sensitive adhesives bymeans of which the coverings are to be secured to the cores.

Now that the principles of the invention have been example, the coreinserts may be made of steel or other materials. As shown in Fig. 3, thecore inserts may themselves form shaft extensions for the roller. Thus,the insert 26 may have a cylindrical end portion 27 which can beadhesively secured to the inner wall of the core 11 with the innersurface of a flange 28 abutting an end of the core 11. As in Fig. 1,glue-carrying passages 26a are provided. The end 29 may have a diameterdiffering from the end 27 and will form the bearing support for thedampening roller.

In each modification of the invention, it is to be noted that thecylindrical core 11 is of a substantial thickness, at least one-thirdthe diameter of the dampening roller taken from its center to the regionof the glue line for its covering of water-carrying material. It is tobe further noted that the core is water-resistant. When made of multiplelayers of paper, either spirally or convolutely wound, it is treatedwith a water-resistant material. The core may also be made up ininexpensive core material other than spirally wound paper so long as ithas the adequate strength and thickness obtained by the multiple layersof adhesively coated paper mentioned above. Thus, the structure of thepresent inven tion is to be contrasted with that heretofore utilized inrollers of the type used for roller-painting and the like. While inroller-painting a generally circular configuration will be satisfactory,for a dampening roller it is essential that the roller throughout itslength be rigidly circular. By providing substantial thickness, at leastonethird the diameter, there are provided both adequate strength andretention within close tolerances of a circular shape throughoutincremental lengths of the roller. Thus, there has been achieved at lowcost a truly cylindrical roller carrying the dampening material neededfor the printing operations.

In Fig. 4 a shaft 15 is provided with an outwardly extending flange 16having tangs or pointed projections 16a or other projections extendinginwardly into the core 11 for driving engagement therewith. On theopposite end of the shaft 15, there is disposed a companion flange 17also having tangs 17a impaling the core 11 and forming a drivingengagement therewith. The flange 17 after being pressed into theillustrated position is secured to shaft 15 by a set screw 18. It willbe obvious from the above description that the dampening roller may bereadily removed by loosening the set screw 18 and sliding it from theshaft 15, the replacement operation being but a reversal of theforegoing steps.

Where existing machines utilize both a solid shaft 20 and a metalcylindrical core 21, Fig. 5, within the dampening roller (not shown inFig. the core inserts 22 and 23 may be of steel or a plastic such as oneof the abovedescribed resins. They have been illustrated as a metal,such as steel. They include fangs 22a and 23a for engagment with thecore 11, not shown in Fig. 5. Each core insert includes an innercylindrical portion 22b and 23b which, like the inserts of Fig. 1,terminate in outwardly extending flanges having on their outer faces thedriving elements or projections, like those shown in Fig. 2, forcooperation with driving members of the printing machinery. The flange22 is secured to the cylindrical member 21 by screws 25, while flange Z3is secured to member 21 by tapered pins 30 extending radially thereof.

It is again emphasized that the present invention is characterized byits simplicity and by the avoidance of complicated clampingarrangements, threaded elements of all kinds, and by the presence ofprefabricated end arrangements in driving engagement with the core andof the configuration required for the particular offset machine in whichthe dampening roller is to be utilized,

What is claimed is:

1. For carrying water to the printing plates of an offset printingmachine, a dampening roller comprising a rigidly circular cylindricalcore having a minimum thickness of at least one third its diameter toprovide retention within close tolerances of a circular shape throughoutincremental lengths of the roller during operation thereof, and havingan opening extending axially thereof, a water-carrying outer coveringadhesively secured to said core by a water-resistant cement, saidcovering being selected from the group consisting of molleton, velveteenand pile fabric, core inserts extending inwardly into said opening fromopposite ends of said core, and means forming a driving engagementbetween said inserts and said core for driving said core, each of saidcore inserts having flanges engaging opposite ends of said core, saidcore being water-resistant, and said core inserts having driving lugsprojecting axially thereof for positive drive of said core in applyingwater to the printing plates.

2. The dampening roller of claim 1 in which said inserts have openingscoaxial with the core for support of the core on a shaft.

3. The dampening roller of claim 1 in which said core is made up ofmultiple layers of paper adhesively secured together in spirally-woundrelationship and shaped into a core which is uniformly circularlengthwise thereof.

4. The dampening roller of claim 3 in which said multiple layers ofpaper are provided by winding the paper upon itself to produce at leastsaid minimum thickness of said core.

References Cited in the file of this patent UNITED STATES PATENTS102,104 Forsyth et al. Apr. 19, 1870 563,572 Day July 7, 1896 1,528,956Smith Mar. 10, 1925 1,789,244 McCollum Jan. 13, 1931 2,344,017 AshpesMar. 14, 1944 2,393,097 Fox Jan. 15, 1946 2,426,401 Mack Aug. 26, 19472,915,006 Howe Dec. 1, 1959 2,924,838 Jones et al. Feb. 16, 1960 FOREIGNPATENTS 609,298 France May 8, 1926

1. FOR CARRYING WATER TO THE PRINTING PLATES OF AN OFFSET PRINTINGMACHINE, A DAMPENING ROLLER COMPRISING A RIGIDLY CIRCULAR CYLINDRICALCORE HAVING A MINIMUM THICKNESS OF AT LEAST ONE THIRD ITS DIAMETER TOPROVIDE RETENTION WITHIN CLOSE TOLERANCES OF A CIRCULAR SHAPE THROUGHOUTINCREMENTAL LENGTHS OF THE ROLLER DURING OPERATION THEREOF, AND HAVINGAN OPENING EXTENDING AXIALLY THEREOF, A WATER-CARRYING OUTER COVERINGADHESIVELY SECURED TO SAID CORE BY A WATER-RESISTANT CEMENT, SAIDCOVERING BEING SELECTED FROM THE GROUP CONSISTING OF MOLLETON, VELVETEENAND PILE FABRIC, CORE INSERTS EXTENDING INWARDLY INTO SAID OPENING FROMOPPOSITE ENDS OF SAID CORE, AND MEANS FORMING A DRIVING ENGAGEMENTBETWEEN SAID INSERTS AND SAID CORE FOR DRIVING SAID CORE, EACH OF SAIDCORE INSERTS HAVING FLANGES ENGAGING OPPOSITE ENDS OF SAID CORE, SAIDCORE BEING WATER-RESISTANT, AND SAID CORE INSERTS HAVING DRIVING LUGSPROJECTING AXIALLY THEREOF FOR POSITIVE DRIVE OF SAID CORE IN APPLYINGWATER TO THE PRINTING PLATES.